Cannabis-based medicines showed subjective improvement in MS spasticity despite mixed results on clinical scales | Research

The takeaway

A review found cannabis-based medicinal extracts (CBMEs) improved patient-reported spasticity in multiple sclerosis, though objective measures like the Ashworth scale often showed no significant effect.

Read this if you want to understand the evidence for using cannabis-based medicines to manage MS spasticity.

Subjective improvement reported despite mixed objective measurements

What the researchers found

The review examined clinical trial evidence for cannabis-based medicinal extracts (CBMEs) in treating spasticity associated with multiple sclerosis (MS).

Patients consistently reported subjective improvement in spasticity when using CBMEs. However, objective measurements using the Ashworth scale (a clinical rating of muscle resistance) generally showed no significant effect. The authors noted that the validity of the Ashworth scale itself had been questioned.

Side effects were generally mild, including dry mouth, dizziness, drowsiness, nausea, and intoxication. Most clinical trials ran for only months, and long-term safety data were limited.

The review flagged particular caution for adolescents, people predisposed to psychosis, and pregnant women.

Why it matters

The disconnect between patient-reported improvement and objective clinical measures highlighted a challenge in evaluating cannabis-based medicines and raised questions about which outcome measures best capture treatment benefits.

The numbers in context

Mild adverse effects reported: dry mouth, dizziness, somnolence, nausea, intoxication. Most trials ran for months. Ashworth scale generally showed no significant effect despite patient-reported improvement.

How the study worked

Narrative review of clinical trial data examining cannabis-based medicinal extracts for MS-related spasticity, published in Therapeutics and Clinical Risk Management.

What this study cannot tell us

Narrative review without systematic methodology. Reliance on subjective outcomes. Limited long-term safety data. The Ashworth scale limitations make it difficult to assess true objective efficacy.

How to read the evidence

Narrative review synthesizing clinical trial data with acknowledged limitations in outcome measurement.

When this study was published

Published in 2010. Nabiximols (Sativex) has since been approved in multiple countries for MS spasticity.

The bigger picture

This review contributed to the evidence base that led to cannabis-based medicines being approved for MS spasticity in several countries, despite the measurement challenges.

Questions still open

What is the best way to objectively measure spasticity improvement? Would longer-term trials reveal additional benefits or risks of CBMEs?

Common questions

Do cannabis medicines help with MS muscle stiffness?

Patients consistently reported improvement in spasticity, but clinical rating scales often showed no significant objective change. The mismatch may reflect limitations of the measurement tools rather than lack of true benefit.

What are the side effects of cannabis-based MS treatments?

The review found mostly mild side effects: dry mouth, dizziness, drowsiness, nausea, and intoxication. Long-term safety data beyond a few months were limited.

Read the original research

New approaches in the management of spasticity in multiple sclerosis patients: role of cannabinoids.

Therapeutics and clinical risk management, 6, 59-63

View on PubMed ↗

Citation

Smith, Paul F. (2010). New approaches in the management of spasticity in multiple sclerosis patients: role of cannabinoids.. Therapeutics and clinical risk management, 6, 59-63.